In the prior art, a magnetic coil is formed by winding a magnetic cable around a support. After a layer of insulating enamel covering the magnetic cable is partially removed, the cable is welded to the support.
The tendency in the prior art is to reduce the cross-section of the cable so as to increase the number of turns that compose the coil. Due the increasingly small dimensions of the cable, however, the known technique of welding the cable to the support increasingly leads to the cable catching fire or not making electrical contact if the cable is not welded correctly. Furthermore, under severe use conditions, it is possible that mechanical stress such as strong vibrations can break the welds, interrupting the electrical connection.